Rotary cutting tool



h ly 19 1927 CQG. scHULLER vROTARY CUTTING TOOL Filed June 28. 1926 u n n lwwntoz CML 5L 5 Patented July 19, 1927.

UNITED STATES CARL G. SCH'ULLER, 0F BREC'KSVILLE, OHIO.

ROTARY CUTTING TOOL.

Application filed .Tune 28, 1926. Serial N0. 118,940.

This invention relates to cutting tools for sott, semi-soft or solid material, particularly for sculpturing wax patterns for dental restorations. In 'making plate restorations the sides of the inished plate next to the tongue, cheeks and lips should conform as nearly as possible to the original contour of the mouth. The usual method employed includes the step of placing wax over the pattern and gouging out concavities therein, following the shape of the patients mouth, as nearly as possible by reference to the original plaster cast. Suitable wax is of such a consistency that it cannot be plastically moulded and hence :it has hitherto been vnecessary to perform this sculpturing with a narrow blade. This was of course. a very tedious operation. It has. been attempted to use tools similar to a dental burr, driven in the usual manner. for working such wax, but hitherto no rotary tool has been successfully used for the reason that the severed material almost immediately clogs the blades and renders the tool use less. This is mainly due to the fact that the cutting blades of such tools have not been made with enough clearance for chips and for the further reason that the blades are of such shape that the severed material is not properly ejected clear of the main body of material.

The primary object of my invention is to provide a rotary tool for sculpturing material such as wax, which tool will not clog. A -further object is to provide a tool head suitable for the above purpose which may be readily made from a single piece of sheet metal. f

Further objects include the provision of a rotatable tool which will eject the severed material backwardly alougt-he axis of rotation. Anot-her object is to provide a tool which will eject the severed material when used for lateral as well as for endwise cutting, whereby the pattern may be more evenly and accurately followed.

Further advantages will become apparent from the following description of my invention which relates to the accompanying drawing, showing the preferred form. The essential characteristics will be summarized in the claims.

In the drawing Fig. l is a side elevation 5 of my tool, aportion of. the shank being broken away. Fig. 2 is a plan view of the tool head. Fig. 3 is a cross section, taken along the line 3 8 on Fig. 2 showing the transverseshape of the blades. Fig. 4 is a radial cross section taken along the line P-l on Fig. 2. Fig. 5 is a perspective view of the tool mounted for operation. Fig. 6 shows an alternate method of attaching the tool head to the shank.

In carrying out my invention I preferably employ a single piece of sheet metal having a central body portion l and bladesv 2. The body portion as shown in Figs. 1 and 4 is cupped as at 8 and from the brim of the cup the blades extend Aupwardly and outwardly. TheV blades are shown as twisted substantially along a non-radial line, this line being indicated in Fig. 2 at L. As a result of such twisting, that portion of Aa lgiven blade which lies toward the axis of rotation is a gradual upward curve. while kbeyond the line L the blade curves downwardly, the shape beingshown most clearly in Fig. 1. The downwardly extending portion of the blades is indicated at 2a. It will be apparent that when the tool vis rotated, the chips will be held against being thrown directly outwardly since they will be for the most part constrained to move along the blades in the concavity or channel. leading backwardly from the cutting edges (the bottom of such channel vbeing substantially along the' line L) until they are thrown clear of the tool in the general direction of the shaft.

The preferred contour of the blades is shown in Fig. 2. It will be noted that each blade is inclined forwardly toward the direction of rotation. the front edge ofeach blade extending substantially in a straight line at 2b and then 'abruptly curving 4as at 2c, the edge adjacent such abrupt curve extending backwardly at the rear of the blade in a gradual curve as at y21. The front edge., the abrupt curve, and a portion of the gradual rearward curve may be sharpened as for example by' grinding as at 5. As shown in Figl these sharpened edges rise from a plane normal to the shaft to .about the central portion of the abrupt curve and then recede (in a direction parallel to the stem) to provide fa lateral cutting edge. The purpose of this is to enable the operator tok cut laterally straight into the wax, or'by turning the head in its -own plane, to cut laterallyin a curve if desired.y

In Fig. 4t I have shown a convenient method of attaching the head to a driving shank indicated at 8. This consists in providing a generous shoulder 9 'against which the central body portion rests, the end of the shank being simply riveted over beyond the opening l() in the body portion as ll. It desired the shank may be Yformed as shown in Fig. 6, namely fwith aslightshoulder 'l/l and reduced end 13, in which case the central body portion oi the head would be formed into a tube. 14; Fitting over the cyl* inder l?) 'lior lateral support. The 'forward end olf the shanlrmay be riveted over as beitoi'c or a small quantity ot solder may be attached to both the end ot the shank and to the sheet metal of the head as at 11a.

Fig. 5 shows the tool in operation and the relative size thereof tothe human hand. It is to be understood, however that dilterent sized tools may be used as required, a larger tool serving best tor roughing` out the work anda smaller one beingI used tor forming narrow concavities to more accurately copy the pattern. A smaller tool, for example, is best adapted `to shaping the wax leading up close to and between tlie'ai'tilicial teeth.

Bythe use ol' my tool and with a small amount oi practice the operator is enabled to copy the natural undulations of the gum adjacent the teeth, almost line t'or line, with surprising speed yas compared with the old method. The tool head is shown in'Itig. 5 as making an cndwise'cut in the coating ot wax designated M, in which use the sharpene-'d edges 2b and 2C are active. To cut a narrower groove the same `tool maybe turned -so tlgiat substantially the only active cutting redge is that `designated 21. In this latter use it will be seen that .the chips will not clog the tool, since the severed chips will be cmistrained to follow along the bottoms 'of the concavities otl the blades. namely sub# stantially along the line L and hence will be for the most part thrown backwardly along the stem.

vlWhile I have described in detail the eX- act contour of the blades shown, I do not wish to be limited thereto since I believe that rI am ,the -l'i-rst to. make a tool Afor this purpose that may be conveniently termed f lroin sheet metal. The contour of the blades while following my general scheme of constrw'ion nia-y moreover be varied `according to the consistency the material to be cut since harder materialwill call ttor a less steep pitch. than sott Wax.

Having thus described `my invention, I

claim: Y f v blades being twisted along a noii-radial line to provide a concavity extending substantially entirely across the blade in such manner as to guide and deflect chips inwardly from such perimetrical line and baclwardly in the general direction otl the shaft.

2. A sheet instal tool for gouging or earvingl sollt Ysolid material, coinprisiiio` a head oortionand a sha-nk said head volition consistiing oil a single piece ot sheet metal li'aving a. central body portion and blades eX- tonding "forwardly out of the. plane of the body portion and then outwardly, `each of said blades being rounded at its `outer end and twisted to provide cutting edges at-thc end thereof in different transverse planes.

8. A tool comprising a driving shaft and a head provided wit-li separated blades, each blade being` sharpened at its outwardly disposed edgos and each blade being vtwisted whereby the sharpened edges are 'disposed in diilerent transverse planes to enablethe tool to cut laterally of the sha-ft when rotated and to forcibly eject-the sevcredinaterial away from the material to be operated upon,

4,. A rotary sheetinetal tool tor gouging .or carving sott material, suoli .as wax, coinprising a central portion havingl blades eX- tending outwardly therefrom and twisted, along a non-radial line, said blades being.V

rounded at their ends and having sharpened edges extending along the .rounded ends, whereby the tool may gouge the material along yditerent edges while being .turned through an angle of or more degrees about an axis lying along vits plane ,of rotation. u ,v

5.*,A tool for cutting and forming soft material coiiiprisinga single ,piece of sheetmetal having a central `body portion, adapted vto be secured to a drive shaft,an'd outwardly extending blades said blades being twisted to proyide a cutting edge the vforward cutting edges ot each blade ,being inclined forwardly from its root with freier-A ence to a radial line through thecenter .otrotation, the en'd contourot` lthe blade adjacent such cutting edge being abruptly c uryed, and the heel ofthe blade leading backward to the body portion in a more 'gradualcurve 6. rotary sculpturing tool comprisinga single piece of sheet metal vhaving twisted blades inclined toward ythe direction 4otrotation andbeing coneaye, the concaviti'es yei:- tending` substantially along non-radiallines and entirely across the respective blades,

7. A tool for dental sculpturing in sott' material comprising a single piece of metal having a central. cup-shaped body portion, adapted to bey secured to drive'shaft, and

upwardly and outwardly'entending blades,v

contiguous with the brimA ofthe cup.,` said blades being separate from. each other-at Such brim and'warped yto provider Alateral y cutting ,edges Iand inclined chip ejectingsuriio aeesa whereby the Chips may be thrown or ibly backward Clear of the Work when the tool is rotated.

S. A rotaryv tool Comprising a sheet metal head having` lSeparated twisted blades eX- tending thereit'roni and sharpened at their edges, the head being centrally apertured to receive a Stem, a stem for supporting the head having its end formed on two diame- 10 ters to provide a shoulder, the body of the tool being substantially iush with the extreme end surface of the Stem, and means for securing the stem and body portion together consisting of material such as solder extending in overlapping relation to the end of the stein and said head.

vIn testimony whereof, I hereunto affix my signature.

CARL G. soi-inLLnR. 

